地铁区间隧道事故工况射流通风的研究

发布时间：2018-05-07 01:34

本文选题：地铁区间隧道 + 射流通风　；参考：《重庆大学》2014年硕士论文

【摘要】：地铁是现代城市交通系统中非常重要的组成部分，对缓解大城市的交通拥堵问题有重要意义。地铁车站及地铁列车人流密集度大，一旦发生阻塞或火灾事故，会对人员的生命财产造成极大威胁。射流通风是解决这一问题的重要方法。因此，对地铁区间隧道事故通风进行深入的研究，具有极大的现实意义和实用价值。本文以地铁区间隧道为研究对象，通过对物理模型的详细描述，以区间隧道实际尺寸为基础，建立了数值计算模型。用Fluent软件对隧道射流通风效果、列车阻塞工况最佳通风速度、列车中部火灾排烟及壁龛安装尺寸对射流风机升压力的影响进行了计算，并以计算结果为基础对其进行了分析。首先，通过现场实测对数值计算的准确性进行验证。现场实测针对深圳地铁三号线，实测结果与模拟结果的对比显示二者具有很好的一致性，说明采用数值方法对地铁区间隧道进行研究是可行的、结果是可靠的。其次，采用本文所建的计算模型对地铁列车在区间隧道阻塞工况最佳通风速度进行了计算。计算原型为重庆市地铁三号线，根据车辆外形、隧道尺寸及重庆的气象条件设置边界条件。通过模拟计算可知，当机械通风时，隧道内空气温度随送风速度的增大而降低。针对重庆，采用2.21m/s的机械通风风速即可将隧道内温度降低至地铁设计规范规定的列车顶部最不利点的最高温度限值以下，保证列车冷凝器的正常工作。同时，，对地铁列车中部火灾的排烟进行了分析。计算模型仍然为重庆市地铁三号线。火源设置在列车中部，强度为10MW，发生火灾时列车位于隧道中部，隧道两端为出口。根据车辆外形、隧道尺寸及重庆的气象条件设置边界条件。通过模拟计算可知，针对重庆地区，当机械排烟风速为6.5m/s时，CO有毒气体的浓度和烟气的温度均没有达到对人体造成直接危害的程度。采用该通风流速，不仅有效的控制了烟气回流、保证了火灾烟气上游乘客的安全疏散，还减少了火灾烟气下游的乘客受高温烟气和CO有毒气体直接危害的程度，减少不必要的伤亡。最后，分析了壁龛安装尺寸对射流风机升压效果的影响。对不同的壁龛角度（θ=30°、40°、50°）、壁龛深度（a=1m、1.2m、1.5m）、壁龛段长度（b=7m、9m、11m、13m、15m）等因素进行组合，得到45种情况。对所有情况下，有壁龛安装和无壁龛安装时射流风机有效升压力和诱导段长度进行对比分析，不仅得出壁龛安装尺寸对射流风机升压效果的影响，而且得出兼顾使射流风机获得最大升压力和壁龛开挖量取得最小值的设计方案，尽可能的降低工程造价。
[Abstract]:Subway is a very important part of modern urban traffic system, which is of great significance to alleviate traffic congestion in big cities. The density of passenger flow in subway stations and trains is very high. Once there are congestion or fire accidents, the lives and properties of people will be threatened greatly. Jet ventilation is an important method to solve this problem. Therefore, it is of great practical significance and practical value to study the accident ventilation of subway tunnel. This paper takes the subway tunnel as the research object, through the detailed description of the physical model, based on the actual size of the interval tunnel, a numerical calculation model is established. The effect of jet ventilation on tunnel jet ventilation, the optimal ventilation speed under the condition of train congestion, the effect of fire smoke exhaust in the middle of the train and the installation size of the niche on the pressure rise of the jet fan are calculated by using Fluent software, and the results are analyzed based on the calculation results. Firstly, the accuracy of the numerical calculation is verified by field measurement. The comparison between the measured and simulated results of Shenzhen Metro Line 3 shows that the numerical method is feasible and the results are reliable. Secondly, the optimal ventilation speed of subway train in the interval tunnel congestion condition is calculated by using the calculation model established in this paper. The prototype of the calculation is Chongqing Metro Line 3. The boundary conditions are set according to the vehicle shape, tunnel size and meteorological conditions in Chongqing. The simulation results show that the air temperature in the tunnel decreases with the increase of the velocity of air supply when mechanical ventilation is carried out. For Chongqing, the temperature in the tunnel can be reduced to the maximum temperature limit of the most unfavorable point at the top of the train according to the design code of the subway by using the mechanical ventilation wind speed of 2.21m/s to ensure the normal operation of the train condenser. At the same time, the smoke emission from the fire in the middle of the subway train is analyzed. The calculation model is still Chongqing Metro Line 3. The fire source is set in the middle of the train and the intensity is 10MW. When the fire occurs, the train is located in the middle of the tunnel and the end of the tunnel is the exit. Boundary conditions are set according to vehicle shape, tunnel size and meteorological conditions in Chongqing. The simulation results show that the concentration of CO toxic gas and the temperature of flue gas do not reach the degree of direct harm to human body when the wind speed of mechanical smoke exhaust is 6.5m/s. Adopting this ventilation velocity can not only effectively control the flue gas reflux and ensure the safe evacuation of the passengers in the upstream of the fire smoke, but also reduce the degree of the passengers downstream of the fire smoke being directly harmed by the high temperature smoke and the toxic CO gas. Reduce unnecessary casualties. Finally, the influence of niche size on the pressure-raising effect of jet fan is analyzed. The factors of different niche angles (胃 ~ 30 掳~ 40 掳~ 50 掳~ (50), depth of a niche 1 ~ 1 m ~ (1.2) m ~ (-1) ~ (-1) m ~ (-1), length of a niche segment ~ (7 m) ~ (9) m ~ (11) ~ (13) m ~ (15) m) were combined, and 45 kinds of conditions were obtained. In all cases, the effective pressure of jet fan and the length of induced section are compared and analyzed when there is a niche and no niche is installed, not only the influence of the installation size of the niche on the pressure effect of the jet fan is obtained, but also the effect of the installation of the niche on the pressure increase of the jet fan is obtained. In addition, the design scheme of making the jet fan obtain the maximum lift pressure and the minimum value of the niche excavation is obtained, and the project cost is reduced as much as possible.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U231.96;U453.5

【参考文献】